Last year, when the City of St. Paul removed 33 ash trees from the two blocks around my house, they planted a variety of trees to replace them. Some ginkgos, a few crabapples, a few others, but the largest number of trees planted were swamp white oak (Quercus bicolor). It’s a great choice for an urban street tree.
It’s native range covers the southeastern part of Minnesota, mostly near the Mississippi River, extending up toward the Twin Cities. With shifts in climate, it is a more reliable tree now in the Twin Cities and beyond. Interestingly, in the wild, swamp white oak has been listed as being of “special concern” by the state of Minnesota. However, it’s used so much in parks and home landscaping that it’s in no danger of extinction.
The tree has long, heavily serrated, glossy green leaves and deeply ribbed bark. It’s a handsome tree that will grow about 60 feet tall with a relatively open canopy spread of about 50 feet. Its acorns are prolific! The tree performs really well on boulevards, where it must handle salt, big snow piles and ice—not to mention all the neighborhood dogs. It grows at a pace of 1 to 2 feet a year, so it sizes up relatively quickly.
Like all oaks, the swamp white oak is a friend to pollinators. According the the National Wildlife Foundation Native Plant Finder, oaks support more than 300 pollinators in the Twin Cities, including Eastern Tiger Swallowtail butterflies, sphinx moths and many more. They are also a favorite of birds, including Baltimore orioles, northern flickers, woodpeckers and many others.
If you end up with a new swamp white oak in your boulevard, be sure to give the tree adequate water as it gets established. These are trees of wetlands (. . . swamp white oaks) and like full sun and fairly moist soil. They are not picky about soil. Swamp white oaks tend to develop a two layer root system, which allow them to handle wet and even flooding in spring and then dryness in summer. Another great reason to plant them on the boulevard!
What are some of your favorite street trees?